Tracking method for cell phone with positioning device and system thereof

ABSTRACT

A tracking method for a cell phone with a positioning device and the system thereof are described. The longitudinal and latitudinal coordinates of a tracked end in a global positioning system (GPS) are sent to a cell phone of a tracking end via a short message service (SMS). After decoding the short message contents, the longitudinal and latitudinal coordinates are displayed in a geographic information system (GIS) installed in the cell phone.

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No(s). 941102945 filed in Taiwan, R.O.C. on Jan. 31, 2005, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of Invention

The invention relates to a tracking method for a cell phone with a positioning device and the system thereof. In particular, the invention utilizes the SMS (Short Message Service) to transmit the position coordinates from a GPS.

2. Related Art

With rapid development in the cell phone technology, a new function is added to cell phones every now and then. It has evolved from old black-and-white phones to the current color phones, from monotonic bells to the current musics, the packet transmission for WAP web surfing and general packet radio services (GPRS). The cell phone can even record videos just like the DV. In spite of its many functions, the most basic two functions of the cell phones have been existent all the time: conversation and transmiting short messages.

According to statistics, the popularity of cell phones in Taiwan has topped the world. Therefore, the cell phone has become an indispensable tool. Each person has at least one cell phone on the average. A valueable function in the cell phone is to allow the user to find out its position from the closest three base stations by trigonometry. Moreover, geographical information such as food, banks, movie theaters, etc can be transmitted to the user. Sometimes, the base station covers a range of as wide as several kilometers. The error can be as large as hundreds of meters. Thi does not provide the required precision.

Due to recent progress in IC designs and chip productions, manufacturers have developed a global positioning system (GPS) with a small-size chip. Imbedding such a chip in a cell phone enables the cell phone to enjoy the GPS functions. The consumers do not need to spend several hundreds of dollars to carry an additional GPS receiver.

SUMMARY OF THE INVENTION

In view of the foregoing, an object of the invention is providing a tracking method for a cell phone with a GPS and the system thereof. The longitudinal and latitudinal coordinates in the global positioning system (GPS) positioned by a tracking end are sent to a smart phone thereof via the short message service (SMS). After decoding the short message contents, the longitudinal and latitudinal coordinates are applied to a geographic information system (GIS) to obtain the position of the other party.

To achieve the above object, the disclosed tracking system for the cell phone with a positioning device includes a GPS receiving module, a global system for mobile (GSM) communications module, an input module, a central processing unit (CPU), a -display module, and a memory module.

The GPS receiving module receives the position coordinate signals transmitted from the satellites. The GSM communication module sends out the longitudinal and latitudinal coordinates in the SMS. The input module receives settings given by the user. The CPU converts the position coordinate signals into longitudinal and latitudinal coordinates, encodes them into a positioning short message, decodes the coordinates contained in the positioning short message, and determines whether the tracking short message allows tracking. The display module displays the coordinates in the short message on a normal cell phone. If it is a smart phone, then the position of the tracked end can be directly displayed on a map. The position of the user also can be displayed. The memory module stores a phone book and the record of short message transmissions.

Besides, the disclosed tracking method for the cell phone with a positioning device includes the following steps. When a tracking end sends out a tracking short message, the tracked end would receive this short message and checks its source cell phone number to determine whether the tracking is allowed. If it is not a trackable cell phone number, the short message is directly deleted. If it is set as a trackable cell phone number, then the GPS receiving module starts receiving position coordinate signals from the satellites, then the GPS converts the position coordinate signals into longitudinal and latitudinal coordinates, encoding them into a positioning short message, and sending out the positioning short message back to the tracking end. In the end, the tracking end obtains the positioning short message and thus the longitudinal and latitudinal coordinates of the tracked end.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will become more fully understood from the detailed description given hereinbelow illustration only, and thus are not limitative of the present invention, and wherein:

FIG. 1 shows the system structure of the invention;

FIG. 2 is a flowchart of the disclosed method;

FIG. 3 shows an embodiment of the invention;

FIG. 4 is a flowchart of the method for tracking;

FIG. 5 is a flowchart of the method of positioning;

FIG. 6-a shows the format of a tracking short message according to the invention; and

FIG. 6-b shows the format of a positioning short message according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

The system structure of the invention is shown in FIG. 1. It contains the following modules: (A) a GPS receiving module 210; (B) a CPU 220; (C) an input module 230; (D) a display module 240; (E) a GSM communication module 250; and (F) a memory module 260.

The GPS receiving module 210 receives position coordinate signals transmitted from satellite 110. The CPU 220 converts the position coordinate signals into longitudinal and latitudinal coordinates, encodes the longitudinal and latitudinal coordinates and some information (e.g. title, phone number, name, etc) according to a format into a positioning short message, decodes a received positioning short message into the information contained therein, and determines accordingly whether the tracking short message allows tracking. It further controls and coordinates the operation of various peripheral modules.

The input module 230 generally refers to a keyboard or a touch-control pad used to receive the settings and inputs from the user, including the system reset of the GPS, the on and off of the tracking function, the phone number of the tracking end. The input command is sent to the CPU 220 for processing. The module further includes an emegency transmitting key. After the user presses this key, a short message containing the longitudinal and latitudinal coordinates of -the current position are directly sent to a predetermined short message receiving end. The display module 240 refers to the liquid crystal display (LCD) for display text information on a normal cell phone. If it is installed on a smart phone with the GIS, it can direcly display the position of the tracked end 120 on a map. It can also display the position of the user using the information transmitted from the GPS receiving module 210.

The GSM communication module 250 sends out the encoded position coordinate message via the SMS. It contains an RF device, a controller, and digital signal processor. In addition to transmitting and receiving communication signals, it can be further used to receive the positioning signal sent from the posiitoning satellite. The memory module 260 stores a phone book and the record of short message transmissions. On an smart phone 160, it further contains a non-volatile memory, such as the flash memory. Not only does it allow the user to install some necessary programs, such as the GIS, it can further be used to store data to lower the burden of the built-in memory.

For illustration purposes, the drawing only shows those devices that are relevant to the invention. Other modules commonly used in regular cell phones, such as the subscriber identify module (SIM) and power supply module, are not explicitly shown.

The disclosed method is shown in FIG. 2. When the tracking end sends out a tracking short message, it should contain the following fields (see FIG. 6-a):

A header field. This field is filled with a code of a series of special characters to indicate that the short message is in a special format. Once the CPU 220 reads this series of special characters, it immediately knows that this is a tracking short message and decodes it to extract the corresponding information;

A state field. This field is filled with a code to representing a corresponding situation. For example, 01 represents “I am lost,” and. 02 represent “Emergency at home,” and so on;

A name field. This field is used to record the name of the user, stored in advance by the user in the memory module 260 to represent the cell phone;

A phone number field. This field is used to record the phone umber of the user; and

A checksum field. It is used to prevent from receiving erroneous short messages during the transmission process. The checksum can be a Hamming code or a cyclic redundancy check (CRC) code.

After the tracking end 120 receives this short message, it first checks the number of the source cell phone, determining whether the tracking is allowed. If it is not a trackable cell phone number, the short message is deleted directly. If it is set as a trackable cell phone number, then the GPS receiving module 210 receives the position coordinate signals transmitted from the GPS (step 510). The CPU 220 converts the position coordinate signals into longitudinal and latitudinal coordinates (step 520).

The CPU 220 encodes the longitudinal and latitudinal coordinates into a positioning short message (step 530). FIG. 6-b shows the format of a positioning short message. The difference between it and the tracking short message is the additional location field, which is used to record the longitudinal and latitudinal coordinates of the current position of the tracking end 120.

The encoded positioning short message is sent out via the GSM communication module 250 (step 540). Finally, the tracking end obtains the positioning short message from its GPS communication module 250. The CPU 220 decodes to obtain the longitudinal and latitudinal coordinates of the tracked end 120 (step 550). The goal of the disclosed tracking method is therefore achieved.

With reference to FIG. 3, an embodiment of the invention, when a tracked end or a personal calling for help 120 is lost or has an accident, a tracking request can be made from the tracking end. The satellite 110 receives the positioning signal of the current position from the satellite. It sends out the positioning short message via the GSM communication module 250. The positioning short message is transferred to the cell phone of the tracking end via an Internet service provider (ISP) 130. The tracking end can use the position of the tracked end 120 coded in the received positioning short message to find out the corresponding position 140 on the map according to the longitudinal and latitudinal coordinates. If the cell phone is connected to a computer 150 and the computer is installed with a tracking program, then the cell phone can transmit the received positioning short message to the computer to mark down the current position of the tracked end 120 on a tracking map. Alternatively, the tracking end is a smart phone 160, which is built in with a GPS. In that case, in addition to positioning the tracking end, the smart phone can mark the position of the tracked end 120 in a GIS accordingly to the received positioning short message.

FIG. 4 shows the flowchart of the disclosed tracking method. First, the tracked end 120 has to turn on the tracking function on his or her cell phone and sets a trackable cell phone number (step 310) in the memory module 260. If the tracking end sends out a tracking short message (step 380), the tracked end 120 receives this tracking short message (step 320) and checks the number of the source cell phone (step 330). The number is compared with the trackable cell phone number set in the memory module to determine whether the tracking should be granted (step 340). If it is not a trackable cell phone number, the short message is directly deleted (step 350). If it is a trackable cell phone number, then a positioning short message is returned (step 370).

When the tracking end receives the returned positioning short message (step 390), the CPU 220 decodes the positioning short message to obtain the name, phone number, and position coordinates of the tracked end 120 (step 400) and displays them on the display module 240. If the cell phone of the tracking end is connected to a computer 150 or it is a smart phone 160 installed with a GIS, then the position of the tracked end 120 can be immediately displayed on a map.

Aside from letting the tracking end obtain the position coordinates of the tracked end 120, the user can directly press an emergency key to ask for help when in peril. This is illustrated in FIG. 5. When a person encounters an emergency situation, he or she can immediately press the emergency key (step 410).

At this moment, the GPS positioning module 210 immediately receives the coordinate signal of the current position transmitted from the satellite 110 (step 420). The CPU 220 converts the position coordinate signals into longitudinal and latitudinal coordinates, and compiles the longitudinal and latitudinal coordinates into a positioning short message containing an emergency code in the state field. The positioning short message is sent out according to the predetermined cell phone number stored in the memory module 260 (step 430). After receiving the positioning short message (step 440), the CPU 220 immediately decodes it and displays the person, phone number, and position coordinates of the person asking for help 120 on the display screen (step 450). If the cell phone of the short message receiver is a smart phone with a GIS or is connected to a computer, then the position of the person in need 120 is displayed on a map. The GIS further plans a shortest path according to the person in need 120 and the helper, so that the helper can arrive in the shortest possible time. It also automatically returns a message according to the information in the short message. (step 460). This return message ensures that it is not an erroneous call and allows the help to know what is happening.

The reason the invention utilizes the SMS is because it is a function that every cell phone has. Not only it is convenient, the contents of a short message are sufficient to cover the name, longitudinal and latitudinal coordinates, and phone number of the user. Therefore, one may use the short message to readily extract the position of the tracked end 120.

Certain variations would be apparent to those skilled in the art, which variations are considered within the spirit and scope of the claimed invention. 

1. A tracking system for a cell phone with a positioning device to transmit longitudinal and latitudinal coordinates contained in a plurality of position coordinate signals obtained from a global positioning system (GPS) from a tracked end to a tracking end via the short message service (SMS), comprising: a GPS receiving module for receiving the position coordinate signals transmitted from a plurality of satellites; a central processing unit (CPU) for converting the position coordinate signals into the longitudinal and latitudinal coordinates, and encoding and decoding a positioning short message containing the longitudinal and latitudinal coordinates; and a global system for mobile (GSM) communications module for transmitting and receiving the positioning short message.
 2. The tracking system for a cell phone with a positioning device of claim 1 further comprising: an input module for receiving a plurality of settings from an user; a display module for displaying the longitudinal and latitudinal coordinates on the cell phone; and a memory for recording the positioning short messages.
 3. The tracking system for a cell phone with a positioning device of claim 1, wherein the positioning short message includes a format with the fields of: a header, filled with the code of a series of special characters so as to indicate the positioning short message is a special format; a status, filled with a code representing a corresponding situation; a name, filled with a name representing the user; a phone number, recording the phone number of the user; a coordinate, recording the longitudinal and latitudinal coordinates of the cell phone's current position; and a checksum, filled with a checksum code so as to prevent from receiving an erroneous short message during a transmission process.
 4. The tracking system for a cell phone with a positioning device of claim 3, wherein the name is keyed in by the user and stored in the memory module.
 5. The tracking system for a cell phone with a positioning device of claim 1, wherein the positioning short message is obtained from a tracking short message sent from an allowed tracking end.
 6. The tracking system for a cell phone with a positioning device of claim 5, wherein the tracking short message includes a format with the fields of: a header, filled with the code of a series of special characters so as to indicate the tracking short message is a special format; a status, filled with a code representing a corresponding situation; a name, filled with a name representing the user; a phone number, recording the phone number of the user; and a checksum, filled with a checksum code so as to prevent from receiving an erroneous short message during a transmission process.
 7. The tracking system for the cell phone with a positioning device of claim 6, wherein the name is keyed in by the user and stored in the memory module.
 8. The tracking system for a cell phone with a positioning device of claim 1, wherein the display module displays the coordinates in a geographic information system (GIS) installed in the cell phone.
 9. A tracking method for a cell phone with a positioning device, comprising: receiving a position coordinate signal transmitted from a GPS by a tracked end; converting the position coordinate signal into longitudinal and latitudinal coordinates; encoding the longitudinal and latitudinal coordinates into a positioning short message; transmitting the positioning short message to a tracking end; and obtaining and decoding the positioning short message by the tracking end to obtain the longitudinal and latitudinal coordinates of the tracked end.
 10. The tracking method of claim 9, wherein the positioning short message includes a format with the fields of: a header, filled with the code of a series of special characters so as to indicate the positioning short message is a special format; a status, filled with a code representing a corresponding situation; a name, filled with a name representing the user; a phone number, recording the phone number of the user; a coordinate, recording the longitudinal and latitudinal coordinates of the cell phone's current position; and a checksum, filled with a checksum code so as to prevent from receiving an erroneous short message during a transmission process.
 11. The tracking method of claim 10, wherein the name is keyed in by the user and stored in a memory module.
 12. The tracking method of claim 9, wherein the tracking end is a trackable phone number recorded in the memory module.
 13. The tracking method of claim 9, wherein the tracking end has to send a tracking short message to obtain a tracking permission from the tracked end before obtaining the positioning short message from the tracked end.
 14. The tracking method of claim 13, wherein the tracking short message includes a format with the fields of: a header, filled with the code of a series of special characters so as to indicate the tracking short message is a special format; a status, filled with a code representing a corresponding situation; a name, filled with a name representing the user; a phone number, recording the phone number of the user; and a checksum, filled with a checksum code so as to prevent from receiving an erroneous short message during a transmission process.
 15. The tracking method of claim 14, wherein the name is keyed in by the user in advance and stored in the memory module.
 16. The tracking method of claim 13, wherein the positioning short message is transmitted automatically to the tracking end once the tracking short message is received by the tracked end and the tracking permission is confirmed. 